What is it?          Cause          Symptoms          Diagnosis          Treatment          Prevention

There’s a short glossary of technical words at the bottom of the page.

What is it?

Canine distemper is also known as ‘hardpad disease’ (because infected dogs often have a hardening of the pads under their feet) and CDV (Canine Distemper Virus).

It is an air- and water-borne virus of the Paramyxoviridae family (why are medical names always unpronounceable?) – the same family of viruses that causes measles, mumps, and bronchiolitis in humans. It also affects some other species, including lions.

It is highly contagious.

It is present in epidemic proportions in Kolkata’s street dog populations. That’s why it is so important that your house pets are vaccinated against distemper. 

It is usually fatal. 

It can be prevented by vaccination.

Distemper does not affect cats.


Distemper is caused by exposure to infected droplets in the air (e.g. from sneezing) and from infected bodily fluids, including from the nose and eyes, and from faeces and urine. It can also be spread by shared bedding and blankets.

All dogs of all ages are vulnerable, but puppies, older dogs and weaker dogs (particularly those with reduced immunity) are especially at risk.

Incubation   It takes between six and 22 days from exposure for symptoms to emerge. Sometimes a fever appears between three and six days after exposure.

Prognosis   The chance of survival is poor. Some vets report a mortality rate among Kolkata’s street dogs as high as 90%. A previously healthy dog that has been well fed and has a strong immunity has the best chance of survival. Death may occur between two and five weeks after infection.

If the dog survives, it is no longer contagious after it is fully recovered.

Distemper affects the central nervous system. You will often see otherwise healthy adult dogs with a twitch in a hind leg. This is a legacy of distemper and it remains with the dog for the rest of its life.

If one dog in a locality is infected, ALL other dogs in that area are at immediate risk. 


An infected dog will have obvious signs of illness and weakness. It will often find a quiet place to lie down, away from attention, so if you can’t find a dog who you think may be infected, look in nearby garages, side streets, golis, and other secluded spaces.

Symptoms of distemper include:

  • High fever
  • Red eyes
  • Runny nose and eyes
  • Dog is tired and lethargic
  • Dog does not want to eat and loses weight
  • Frequent coughing
  • Vomiting
  • Diarrhoea
  • Fits, seizures and paralysis (in later stages)
  • Salivation
  • Twitching (often in the leg)
  • Thickened and hardened footpads (the pads under its feet) and nose


The virus first appears in bronchial lymph nodes and tonsils two days after exposure. The virus then enters the blood stream on the second or third day. A first round of acute fever tends to begin around three to eight days after infection, which is often accompanied by a low white blood cell count.These signs may or may not be accompanied by anorexia, a runny nose, and discharge from the eye. This first round of fever typically recedes rapidly within 96 hours, and then a second round of fever begins around the 11th or 12th day and lasts at least a week. Gastrointestinal and respiratory problems tend to follow, which may become complicated with secondary bacterial infections. Inflammation of the brain and spinal cord, otherwise known as encephalomyelitis, either is associated with this, subsequently follows, or comes completely independent of these problems. A thickening of the footpads sometimes develops, and… lesions on the abdomen usually develop. Neurological signs typically are found in the animals with thickened footpads from the virus. About half of sufferers experience meningoencephalitis.


In the initial stages of Canine Distemper, the major symptoms include high fever, reddened eyes, and a watery discharge from the nose and eyes. An infected dog will become lethargic and tired, and will usually become anorexic. Persistent coughing, vomiting, and diarrhoea may also occur. In the later stages of the disease, the virus starts attacking the other systems of the dog’s body, particularly the nervous system. The brain and spinal cord are affected and the dog may start having fits, seizures, paralysis, and attacks of hysteria.


Lasting signs    Distemper affects the central nervous system. A dog that recovers fully from distemper will not recover from damage to the nervous system. You will often see otherwise healthy adult dogs with a twitch in a hind leg. This is a legacy of distemper and it remains with the dog for the rest of its life.

  • Twitching
  • Hardened and thickened footpads and nose
  • Eroded teeth and tooth enamel
  • Degeneration of the nervous system (life threatening)
  • Fits (potentially life threatening)
  • Reduced sight
  • Reduced coordination (motor skills)
  • Paralysis (life threatening)

For a dog that has survived distemper, but experiences progressively more severe fits and paralysis, and severely reduced motor skills, to the extent that its quality of life is seriously compromised, the kindest response may be to put the dog to sleep. Consult a vet.


The symptoms listed above – particularly fever, breathing problems, hardened footpads and nervous twitches – may point strongly to distemper. But they may also be symptoms of a different condition. There are blood, urine and serum tests done by your vet that help to reach a diagnosis.


There is no cure for distemper.

You can only treat the symptoms and do what is possible to boost the dog’s immunity.

All viruses reduce immunity. The animal is therefore more vulnerable to secondary infections, which have to be prevented or treated separately.

Some people use an injection called Canglob to boost immunity to help the dog fight the disease. But this only has a success rate of about 30%. It is also very expensive (Rs4,500 for one dose, multiple doses are required). Your vet can advise further.

Loss of appetite/weight and diarrhoea can be addressed by a drip, although there are obvious challenges to doing this in a street dog’s environment. Regularly clean the dog’s runny eyes and nose. Secondary infections may be treated with antibiotics prescribed by the vet.

If you have dogs at home, make sure that they are vaccinated against distemper, because the virus can stick to your hands and clothes even from a brief encounter with an infected dog. 


The only good thing to say about distemper is that it is preventable.

A dog can be vaccinated against distemper after it is 45 days old.

There are several vaccines on the market, including 5L4 made by Pfizer. The most common is called NOBIVAC – DHPPiL. DHPPiL stands for Distemper, Hepatitis, Parvo virus, Para-influenza, Leptospirosis; and the vaccine protects against all these diseases.


  • Abdomen – tummy, belly
  • Anorexia – not eating/losing weight
  • Bronchial lymph nodes – thickened blood vessels in the lungs
  • Encephalomyelitis – inflammation of the brain and spinal cord
  • Exposure – in contact with
  • Gastrointestinal – to do with the stomach and bowels
  • Incubation – time between infection and symptoms
  • Meningoencephalitis – inflammation of the brain and spinal cord
  • Prognosis – forecast, what is expected to happen
  • Respiratory – to do with breathing
  • Salivation – producing spit/saliva in the mouth